Method and apparatus for powering-on a computer-based system via a network interface

ABSTRACT

A network interface card in a networked client computer includes a network interface circuit that decodes and then compares incoming network packet addresses to known address bit patterns, the decoding and comparing circuitry being powered at all times. Receipt and recognition of certain addresses means the client computer must be powered-on, even if manually switched OFF. When such a server-transmitted address is recognized, a power-on signal is issued to a power control unit that causes full operating power to be coupled to the client computer. In this fashion, a server can broadcast power-on signals to a plurality of networked client computers or workstations.

This is a continuation of application Ser. No. 08/499,085, filed Jul. 6,1995, now U.S. Pat. No. 5,809,313. This application is a reissue patentapplication of U.S. Pat. No. 5,958,057, which issued from U.S.application Ser. No. 09/152,634 filed Sep. 14, 1998, which is acontinuation of application Ser. No. 08/499,085 filed Jul. 6, 1995, nowU.S. Pat. No. 5,809,313.

FIELD OF THE INVENTION

The present invention relates to networked computer-based systems, andmore specifically to powering-on such systems using network interfacesignals.

BACKGROUND OF THE INVENTION

A network is used to couple a host server computer to one or more clientcomputers, using wires (including telephone wires), fiber optics, orwireless signals. There are at least several million computers in theUnited States alone, and an increasing number of these computers arebecoming network-accessible.

FIG. 1 depicts a generic network 10 that includes a server 20 and one ormore client computers or workstations 30, 30′ that each include acentral processing unit (“CPU”) 40, 40″. (As used herein, the termcomputer shall be understood to include the term workstation.) Theserver and clients communicate over information paths 50, 50′ that, asnoted, may be wires, optical cables, or radio transmissions. Paths 50,50′ may be parallel, e.g., a plurality of wires, or may be serial, e.g.,a single data line. At the client end, each computer includes a networkinterface circuit 60, 60′.

Network interface controller 60, 60′ typically is an integrated circuit(“IC”) chip that provides interfacing between the client computer andthe remote host/server. According to current Ethernet network protocol,networked computers rely upon three attributes of the network: (a) thenetwork is always up or active, (b) the client computer is always aliveand coupled to the network, and (c) and/or application programs may berun locally or run remotely over the network from another computer. Eachcomputer 30, 30′ includes a power supply that is typically coupled to110 VAC/220 VAC, and whose output DC voltages are coupled through anON/OFF power switch relay, here depicted as a manually operated switchS1, or S1′. If the computer is to communicate with the network, thepower switch is ON, otherwise there is no operating voltage to thecomputer. Although S1 is depicted as a manually operated switch, it isunderstood that power may be switched on or off using other switchingdevices, including electronic switching devices.

A single desktop computer such as computer 30 or 30′ may only consumeperhaps 150 watts of electrical power. However, cumulatively theelectrical power consumed by all of the computers in the United States,and indeed in the world, is becoming appreciable. With a view toreducing this power consumption and the environmental cost involved ingenerating the power, the United States Federal Government haspromulgated the Energy Star program.

As applicable to the present invention, the Energy Star program requiresthat computers be powered-off to a low energy state of less than 30watts consumption during periods of inactivity. Computers meeting thisrequirement, so-called “green PCs”, are permitted to bear an Energy Starinsignia. Conversely, non-Energy Star compliant equipment is often lesswell received in the commercial marketplace.

One approach to complying with the Energy Star requirement is to designlower power consumption equipment, laptop computers, for example. Manycomputers can also benefit from advanced power management features,including features that are incorporated into the computer operatingsystem. Intel Corp. and Microsoft Corp. collectively have promulgatedone such Advanced Power Management specification.

Using power management, a computer can power-down its harddisk and slowits CPU clock rate, thus saving electrical power, after inactivityexceeding a certain threshold. Depressing a key on the computerkeyboard, or moving a mouse or other control device will “awaken” thecomputer, restoring it to full CPU clock rate and/or reactivating thehard disk, within a few seconds.

However, powering-off a networked Energy Star compliant computer duringperiods of inactivity detrimentally interrupts established events thatconstantly occur in a networked computing environment, polling forexample. In practice, powering-off a networked computer could readilymake such a computer a pariah in the network marketplace. It is thusdesirable to maintain some operating power, preferably less than 30watts, to a networked computer to permit the computer to respond to thenetwork without being manually awakened.

It is known in the art to remotely awaken a powered-off computer with afacsimile (“FAX”) signal or a modem signal coupled to the computer'sserial port from the telephone line. However such “awakening” requires aFAX or modem signal to be sent to the specific telephone numberassociated with the computer's modem. The modem must be powered at alltimes and may consume from 5 watts to 10 watts power.

Thus, there is a need to make a networked computer Energy Starcompliant, without risk of interrupting network functions that can occureven during periods of client-system inactivity. Preferably the computershould be capable of being powered-off, and then “awakened” using onlysignals available from the network and coupled to the network interfacecard. Furthermore, there is a need for a mechanism or system by which alarge number of networked computers can be powered-on, quickly or evensimultaneously.

The present invention discloses a method and apparatus for accomplishingthese needs.

SUMMARY OF THE INVENTION

A network interface card in a networked client computer includes asoftware or hardware mechanism that is powered at all times. Thismechanism decodes incoming network packets and recognizes therein aserver-transmitted address whose receipt means the client must bepowered-on, even if it had been manually switched off. The transmittedaddress may be a “broadcast” address whose receipt will cause power-onof all recipient client computers on the network. This address mayinstead be a client-dedicated address whose receipt will cause power-ononly in client computers whose decode and recognition mechanismrecognizes this address.

Within the network interface card, the address comparison may beimplemented in hardware using register comparator logic, or in softwareusing a hashing algorithm. In either event, the decoding and addressrecognizing mechanism operates with less than 30 watts power and ispowered at all times.

Upon receipt, decoding and recognition of a broadcast or client address,the decode and recognition mechanism outputs a signal that activates apower control circuit within the network interface card. The powercontrol circuit is coupled between the DC power source and the client,and activation closes this circuit, bringing full operating DC voltageand thus full power-on to the client.

Full power-on condition will occur within a few seconds, regardless ofwhether the client computer was in a power-off mode or was switched offmanually. The present invention permits a server to broadcast a power-onaddress whose receipt will cause each of a plurality of clients coupledto the network to power-on simultaneously.

Other features and advantages of the invention will appear from thefollowing description in which the preferred embodiments have been setforth in detail, in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a generic network, according to the prior art;

FIG. 2 is a block diagram of a portion of a network interface card andpower control circuitry, according to the present invention;

FIG. 3 is a flow diagram depicting steps in recognizing a networkbroadcast power-on indicating address, and in powering-on a networkedclient computer, according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 2 depicts a client computer (or workstation) 30 that includes a CPU40, and a modified network interface card 200 according to the presentinvention. Computer 30 is coupled, via line or lines 50 to a networkserver 20, such as server 20 in FIG. 1.

Among line(s) 50 are line(s) 90 that can carry packets of informationbroadcast by server 20 to all client computers 30, 30′, etc. coupled tothe network. Although FIG. 2 depicts path 50 as including a plurality oflines including lines 90, e.g., parallel coupling, a single serial line(e.g., a single line 50 or line 90) configuration could instead be used,depending upon the network electrical specification.

The information broadcast by server 20 over line(s) 50 is in packetformat, with each packet comprising a number of bytes. Packet size maybe 48 bytes in certain protocols, each packet including an address fieldof 6 bytes, or 48 bits. In some protocols, the first 24 bits of anaddress field are organization address blocks, which contain bitpatterns unique to the organization producing the hardware. Someorganization address blocks are defined on an industry-wide basis. Forexample, within the IEEE Ethernet protocol, a string of 24 0's denotes anull packet, which recipient clients may ignore.

As described below, the present invention utilizes client receipt andrecognition of certain server-transmitted address patterns to commandpower-on within a recipient networked client, even if the client hadbeen manually turned-off.

Referring to FIG. 2, DC operating power to computer 30 is provided by aninternal power supply (not shown) on line 70 that is coupled by a switchmechanism, here shown as a switch S1, into the computer at node 80. Ifswitch S1 is in the OFF position, operating power to computer 30 isinterrupted. However, a small amount of operating power is still coupledto at least a portion of a network interface circuit 100 via a powerlead 110, and is also provided as an input to a power control circuit130. Alternatively, a split power plane or a battery could be used topower the network interface circuit 100. Circuit 100 is powered at alltimes and will consume less than 30 watts mandated by the Energy Starprogram. Actual circuit 100 power consumption depends upon the nature ofthe server-to-client coupling but will typically range from 5 watts to10 watts.

If switch S1 is in the ON position, computer 30 receives full operatingpower, with CPU 40 being coupled via lead 85 to powered node 80.However, computer 30 may enter energy saving modes in which the computerhard disk (not shown) ceases rotation, and in which CPU 40 is clocked ata relatively slower rate, or completely halted.

It is to be understood that full operating power need not pass throughswitch S1, and that node 80 may in fact be the input node of a latchdevice within computer 30. Upon receipt of a DC signal at node 80, suchlatch device can switch the full operating power on to power computer30.

Network interface circuit 100 is coupled by line (or lines) 90 to server20, and to client CPU 40 by the local CPU data bus 45. Operating poweris always available to circuit 100 via a power lead 110 that comes fromthe power source side of switch S1.

Circuit 100 includes an address decoder 102 and a comparator 104 thatcompares the decoding incoming address received via line(s) 90 against astored bit representing an address whose receipt means computer 30should enter power-on. The comparator could, for example, include logicallowing a user of computer 30 to program not only the addresses to berecognized, but also to determine whether power-on should occur even ifrecognition is made. At a minimum, the portion of circuit 100 includingdecoder 102 and comparator 104 receive operating power at all times, butthe rest of circuit 100 need not be powered at all times. Of courseseveral such address bit patterns may be stored, including for example,a broadcast address pattern and a client address pattern.

Comparator 104 may be implemented in hardware using conventionalhardware registers and comparator logic. Alternatively, comparator 104may be implemented in software to shorten comparison time and reducecost of implementation and/or power consumption. In a softwareimplementation, comparator 104 includes a hash table and will firstcompare most significant bit portions of an incoming packet address. Ahashing algorithm is executed within the interface controller unit. Ifmatched, less significant bit portions are compared until a completebroadcast or client address match is recognized.

However implemented, if unit 100 recognizes an address match, a“power-on” signal is coupled over lead 120 to the input of a powercontrol unit 130 that is coupled in parallel across switch S1. Powercontrol circuit 130 may be a single power control integrated circuit(“IC”), a MOSFET switch, or other latch-accomplishing mechanism.

Upon receipt of this signal, power control unit 130 “closes”, couplingtogether power-carrying line 110 and line 70 with line 140. CPU 40 nowreceives operating voltage via lead 85, and computer 30 can enter a fullpower-up state within one or two seconds, even if S1 is open.

Thus, when server 20 broadcasts a address over line(s) 90 whose receiptand recognition by circuit 100 commands a power-on of computer 30, unit100 triggers power control unit 130, which provides full operating powerto computer 30. Power-on occurs regardless of whether computer 34 is inan Energy Star low-power mode (e.g., where S1 was in the ON position topower-on computer 30, but has been turned OFF as a result of Energy Starmechanism), or is in a power-off mode (e.g., with S1 in the OFFposition). In the low-power mode, although S1 will have been in the ONposition, CPU 40, hard disk(s) (not shown) and other power consumingcomponents within computer 30 will have entered power saving modes,e.g., operating and using less than 30 watts.

In the above fashion, one or a plurality of client computers 30 may besimultaneously forced to enter a power-on state using addressinformation broadcast by a network server. This is in contrast to theprior art use of a telephone line and modem to dial a dedicatedtelephone number for a given computer to remotely command the computerto power-on.

FIG. 3 depicts the various method steps used to carry out the presentinvention. Initially, at method step 300, it is assumed that S1 is OFF,and that no DC operating potential is coupled to node 80 of computer 30.

At step 310, if switch S1 is ON (or activated), then at step 350 DCpower is coupled to CPU 40 and indeed to computer 30. If, however, CPU40 is inactive for 30 minutes as determined by step 360, Energy Starcompliance mandates that, at step 300, CPU power be interrupted, e.g.,S1 returned to OFF.

Returning to step 310, even if S1 is OFF, unit 100 receives operatingpower and examines incoming address information communicated overline(s) 90.

Within unit 100, if a comparison match is formed between the incomingaddress and a bit pattern known to represent a broadcast addresscommunicating a power-on condition, step 330 returns to step 350 and theCPU power is turned ON by activating power control unit 130 via line120. However, as noted, user-programmable logic may be provided tooverride turn-on, even if a broadcast match occurs. As before, at step360, after 30 minutes of inactivity, the Star Energy-compliant clientwill interrupt CPU power at step 300 by causing S1 to be OFF, and bypower control unit 130 to open circuit.

However, if step 330 does not result in a broadcast address match, atstep 340 a determination is made by unit 100 to determine whether theincoming address represents an address commanding a power-on conditionof this particular computer 30.

If an address match occurs, then at step 350 power control unit isactivated, providing operating DC voltage to computer 30. However, asnoted, user-programmable logic may be provided to override power-on,even if a client address match occurs. Such logic could, if desired,flexibly permit a broadcast address match but not a client address matchto cause power-on, or the converse.

If, however, step 340 does not recognize the incoming address, theroutine returns to step 300 and computer 30 remains off.

Modifications and variations may be made to the disclosed embodimentswithout departing from the subject and spirit of the invention asdefined by the following claims.

1. In a peer-to-peer environment that includes a plurality of memberscoupled to said environment including a member that broadcastsinformation to at least one member whose operating voltage is switchedoff, a method for powering-on the switched-off member, the methodincluding the following steps: providing each said member with aninterface coupled to receive said information, at least a portion ofsaid receiving operating voltage at all times anda network interface ofthe switched-off member receiving said broadcasted information, whereinat least a portion of said network interface is receiving power eventhough a remaining portion of the switched-off member is not, whereinthe network interface includinges a decoder, a comparator, and a powercontrol unit; said decoder decoding a first type of information includedin said broadcasted information; said comparator comparing decoded saiddecoded first type of information with at least one stored informationpattern representing a power-on condition, said comparator outputting apower-on signal to said power control unit when said stored informationpattern matches the decoded said first type of information; said powercontrol unit coupled to provide ing said switched-off member's operatingvoltage to said switched-off member upon receipt of said power-onsignal.
 2. The method of claim 1, wherein said network interface storesat least a first information pattern representing a subset of members ofsaid environment, and a second information pattern representing a subsetof said subset of members of said environment; wherein said comparatoroutputs said power-on signal when the decoded said first type ofinformation matches either of said first information pattern or saidsecond information pattern.
 3. The method of claim 1, wherein each saidmember is Energy Star compliai nt, and wherein collectively said decoderand said comparator consume less than 30 watts of operating power. 4.The method of claim 1, wherein said environment further includes asecond member, receiving said information broadcast by the broadcastingmember, whose wherein the second member's operating voltage isswitched-off, said method powering-on each said member furthercomprising: said second member including a second interface coupled toreceive said information, at least a portion of said second networkinterface receiving operating voltage at all times, said interfaceasecond network interface of the second member receiving said broadcastedinformation, wherein at least a portion of said second network interfaceis receiving power even though a remaining portion of the second memberis not, wherein the second network interface includinges a seconddecoder, a second comparator, and a second power control unit; saidsecond decoder decoding said first type of information included in saidbroadcasted information; said second comparator comparing decoded saidfirst type of information with at least one stored information patternrepresenting a power-on condition, said second comparator outputting apower-on signal to said second power control unit when said storedinformation pattern matches the decoded said first type of information;said second power control unit coupled to provide ing said secondmember's operating voltage to said second member upon receipt of saidpower-on signal; wherein each member is powered-on simultaneously whensaid decoded first type information matches said stored informationpattern .
 5. The method of claim 1, wherein said broadcasted informationincludes packets of binary data.
 6. The method of claim 1, wherein saidfirst type of information includes binary address information.
 7. Themethod of claim 1, wherein said comparator includes implements a hashingalgorithm executed within said interface .
 8. In a peer-to-peerenvironment that includes a plurality of members coupled to saidenvironment including one of said members that broadcasts information toat least a first member and a second member, each of said first andsecond members including an interface, at least of a portion of which isoperative at all times, each said interface able to store at least onetype of information pattern, and having a decoder that decodes at leastone type of information, and a comparator, and having a power controlunit controllably able to provide operating voltage to the associatedsaid member, each of said first and second members having theiroperating voltage switched off, a method for powering-on at least achosen one of said first and said second members, the method includingthe following steps: storing in each said interface at least one of afirst type of information pattern and a second type of informationpattern; causing each said decoder to decodeing broadcast saidtheinformation from the broadcasting member; causing each said decodertocomparator compareing decoded said decoded broadcast informationagainst informationthe first and second information patterns stored insaid decoder's associated said interface; and causing said each saidpower control unit to powering-on each said member whose decodercomparison showscomparator indicates a match between information storedin said decoder's associated said interface said first type ofinformation, wherein said first type of information when decoded andsuccessfully compared commands powering-on .
 9. The method of claim 8,wherein said first type of information pattern represents a subset ofmembers of said environment, and said second type of information patternrepresents a subset of said subset of members of said environment;wherein each said comparator outputs said a power-on signal when thedecoded first type of broadcast information matches either of said firstinformation pattern or said second information pattern.
 10. The methodof claim 8, wherein each said member is Energy Star compliai nt, andwherein collectively each said decoder and associated said comparatorconsumes less than 30 watts of operating power.
 11. The method of claim8, wherein said broadcast information includes packets of binary data.12. The method of claim 8, wherein said first type broadcast informationincludes binary address information.
 13. The method of claim 8, whereineach said comparator includes implements a hashing algorithm executedwithin an associated said interface .
 14. In a peer-to-peer environmentthat includes a plurality of members coupled to said environmentincludes a member that is configured to broadcasts information to atleast one of said members whose operating voltage is switched off, asystem for powering-on a switched off said member, the systemcomprising: an interface of said switched-off member coupled to receivesaid broadcasted information, said interface including a decoder, acomparator, and a power control unit, wherein said decoder, comparatorand power control unit are each configured to receiving e operatingvoltage at all times while a remaining portion of the switched-offmember is not; wherein said decoder is configured to decodinge at leasta first type of information included in said received information;wherein said comparator is configured to comparinge said decoded saidfirst type of information with at least one stored information patternrepresenting a power-on condition, wherein said comparator is configuredto outputting a power-on signal to said power control unit when a saidstored information pattern matches the decoded said decoded first typeof information matches one of the at least one stored informationpattern; and wherein said power control unit coupled tois configured toprovide operating voltage to said remaining portion of said switched-offmember upon receipt of said power-on signal.
 15. The system of claim 14,wherein said interface stores at least a first information patternrepresenting a subset of members of said environment, and a secondinformation pattern representing a subset of said subset of members ofsaid environment; wherein said comparator outputs said power-on signalwhen the decoded said first type of information matches either of saidfirst information pattern or said second information pattern.
 16. Thesystem of claim 14, wherein each said member is Energy Star compliai nt,and wherein collectively for each interface said decoder and saidcomparator consume less than 30 watts of operating power.
 17. The systemof claim 13 14, wherein said environment further includes a secondmember, configured to receiving e said information broadcast by thebroadcasting member, whose operating voltage is switched-off, saidmethod powering-on each said member said system further comprising; asecond interface of said second member including a second interfacecoupled to receive said broadcasted information, at least a portion ofsaid second network interface receiving operating voltage at all times ,said second interface including a second decoder, a second comparator,and a second power control unit, wherein said decoder, comparator, andpower control unit are each configured to receive operating voltagewhile a remaining portion of the second member is not; wherein saidsecond decoder is configured to decodinge said first type of informationincluded in said received information; wherein said second comparator isconfigured to compareingsaid decoded said first type of information withat least one stored information pattern representing a power-oncondition, wherein said second comparator is configured to outputting apower-on signal to said second power control unit when said storedinformation pattern matches the decoded said decoded first type ofinformation matches one of the at least one stored information pattern;and wherein said second power control unit coupledis configured toprovide operating voltage to said remaining portion of said secondmember upon receipt of said power-on signal; wherein each member ispowered-on simultaneously when said decoded said first type informationmatches said stored information pattern .
 18. The system of claim 14,wherein said received information includes packets of digital data. 19.The system of claim 14, wherein said first type of information includesbinary address information.
 20. The system of claim 14, wherein saidcomparator includes implements a hashing algorithm executed within saidinterface .
 21. A computer system comprising: a network interfacecoupled to a plurality of computers, wherein the network interface isconfigured to receive information packets from one of the plurality ofcomputers, and wherein the network interface includes a decoder, acomparator, and a power control unit; wherein said decoder, saidcomparator, and said power control unit receive power; wherein saidnetwork interface is configured to receive said information packets;wherein said decoder is configured to decode address informationincluded in said information packets; wherein said comparator isconfigured to compare the decoded address information with one or morepatterns of bits, and to output a power-on signal to said power controlunit when one of the one or more patterns of bits matches the decodedaddress information; and wherein said power control unit is configuredto pass power from said power source to said client computer system uponreceipt of the power-on signal.
 22. The computer system of claim 21,further comprising a switch unit coupled to a power source, wherein:responsive to the power control unit receiving a power-on signal, saidswitch unit is configured to supply power from the power source to saidcomputer system even if said computer system is powered off or in alow-power mode.
 23. The computer system of claim 21, wherein saidnetwork interface consumes less than 30 watts of power when saidcomputer system is in a power off mode.
 24. The computer system of claim21, wherein said comparator comprises a hashing mechanism.
 25. Thecomputer system of claim 21, wherein said comparator comprises registercomparator logic hardware.
 26. The computer system of claim 21, wherein:said one or more patterns of bits are stored in said network interfaceand include at least a first pattern of bits associated with a broadcastaddress and a second pattern of bits associated with a client address;and wherein said comparator is configured to output a power-on signalwhen the decoded address information matches said first pattern of bitsor said second pattern of bits.
 27. The computer system of claim 21,wherein: said power control unit is selected from a group consisting of:(i) power control integrated circuit, (ii) a MOSFET switch.
 28. Thecomputer system of claim 21, wherein said network interface is locatedon a card.
 29. A method comprising: a network interface included in acomputer system coupled to a network receiving an information packetincluding a bit pattern from a server computer system coupled to saidnetwork, wherein the receiving occurs while the network interface isreceiving power but a remaining portion of the computer system is not,wherein the network interface includes a decoder, comparator, and apower control unit; said decoder decoding said received bit patternincluded in said information packet; said comparator comparing saiddecoded bit pattern with at least one bit pattern stored in said networkinterface and outputting a power-on signal to said power control unitwhen the decoded bit pattern matches one of the stored bit patterns; andsaid power control unit passing power to the remaining portion of saidcomputer system upon receipt of said power-on signal.
 30. The method ofclaim 29, wherein said power control unit supplies power to saidcomputer system responsive to said power-on signal, even if the computersystem is powered off or in a low-power mode.
 31. The method of claim29, wherein the at least one bit pattern includes at least a first bitpattern associated with a broadcast address and a second bit patternassociated with a client address, and wherein said comparator outputssaid power-on signal when said decoded bit pattern matches said firstbit pattern or said second bit pattern.
 32. The method of claim 29,wherein the information packet includes broadcast address informationassociated with a plurality of computer systems coupled to the network,and wherein the information packet is transmittable to each of theplurality of computer systems to cause each of the plurality ofcomputers to receive power.
 33. A method comprising: a network interfaceof a client computer system receiving one or more information packetsfrom a server computer system, wherein the receiving occurs while atleast a portion of the network interface is receiving power but aremaining portion of the client computer system is not, wherein thenetwork interface includes a decoder, a comparator, and a power controlunit; the decoder decoding address information included in the one ormore information packets; the comparator comparing the addressinformation with one or more stored bit patterns; the comparatoroutputting a power-on signal to the power control unit when the addressinformation matches one of the one or more stored bit patterns; and inresponse to the power control unit receiving the power-on signal, thepower control unit providing the remaining portion of the clientcomputer system power.
 34. A method comprising: a server transmittingpacket information to a first network interface over a network, whereinthe first network interface is included in a client computer, whereinthe first network interface includes a decoder, a comparator, and apower control unit and is configured to receive power even while aremaining portion of the client computer is not, wherein thetransmitting occurs while the first network interface is receiving powerbut a remaining portion of the client computer is not; wherein thetransmitting causes: the decoder to decode the packet information; thecomparator to indicate to the power control unit whether the decodedpacket information matches one or more predetermined values; and theremaining portion of the client computer to receive power based on theindication.
 35. The method of claim 33 wherein the packet information istransmitted over the network to respective network interfaces includedin a plurality of other client computers, wherein each of respectivenetwork interfaces is receiving power while the remaining portions ofthe plurality of other client computers are not; and wherein the packetinformation is addressed to a broadcast address, wherein one of the oneor more predetermined values corresponds to the broadcast address, andwherein the transmitting also causes the remaining portion of each ofthe plurality of other computers to receive power.
 36. A methodcomprising: a network interface of a client computer system receivingone or more data packets from a server computer system, wherein thereceiving occurs while at least a portion of the network interface isreceiving power but a remaining portion of the client computer system isnot; the network interface comparing information in the one or more datapackets with one or more stored bit patterns; in response to thecomparing resulting in a match, the network interface causing theremaining portion of the client computer system to receive power.